Antenna wire tension and ejecting unit



March 4, 1958 F. A. VER'GA ANTENNA WIRE TENSION AND- EJECTING UNIT IFiled Jan. 6, 1956 INVENTOR fiamfAJzya BY 9% G W ATTORNET United StatesPatent ANTENNA WIRE TENSION AND EJECTlNG UNIT Frank A. Verga, Towson,MtL, assignor to The Glenn L. Martin Company, Middle River, Md, acorporation of Maryland Application January 6, 1956, Serial No. 557,742

12 Claims. (Cl. 24-291) The present invention relates to a device forholding an antenna wire under tension and more particularly to a deviceof this character which will function to eject an antenna wire in theevent of loss of tension resulting principally from failure of theantenna wire.

It is an object of the present invention to provide a device formaintaining an antenna wire under tension and for ejecting a broken wirewhich functions in a simple and expedient manner with a minimum ofmoving parts. The device is particularly adapted for use with aircraftand includes means for automatically ejecting an antenna wire which haslost its tension due to becoming parted or broken. It will be apparentthat the ejecting feature of the device will prevent the antenna wirefrom interfering with other parts of the means upon which it is mounted.In the case of an aircraft, it is known that the antenna wire may faildue to a variety of factors including fatigue or breakage by contactwith foreign elements. In the event failure occurs in flight, there isthe danger that the broken antenna wire can become wrapped around theempennage of the aircraft interferring with the control of the aircraftand thus increasing greatly the accident hazard of the airplane.

It is a further object of the present invention to provide an antennawire tension and ejecting unit which will prevent a broken antenna wirefrom becoming wrapped around a control element of the aircraft uponwhich it is mounted and thereby greatly reduces the accident hazard ofthe aircraft by automatically ejecting any broken antenna wire. I a

Other and further objects of the invention will become more fullyapparent from the following detailed description when taken inconjunction with the drawings in which:

Figure 1 is a view in section through an antenna wire tension andejecting unit designed according to the present invention showing theunit loaded and in use;

Figure 2 is a view in section taken along line 2--2 of Figure l; and

Figure 3 is a view in elevation showing a stable condition of the unitduring loading.

Referring now to the drawngs in detail, a preferred embodiment of thepresent invention will be described. ,The device consists of a barrelwhich is internally threaded and which telescopically and threadinglyengages with an externally threaded sleeve 11 apertured at its lowerend.

Projecting through the aperture is a bolt 12 fixed at one end to asuitable bracket 13 which facilitates mounting of the unit to anaircraft. The other end of bolt 12 is threaded and receives a washer 14and a nut 15. The top end of the barrel 10 is apertured and a graduatedrod 16 projects through the aperture. Attached to the lower end of thegraduated rod is a piston 17 which is held in position on rod 16 bymeans of a nut 18 threaded onto the lower end of the rod 16. Acompression spring 19 is fitted around the rod 16 and bears against thepiston 17 at one end and against the inner surface of the top of thebarrel 10 at its other end.

A safety lock barrel 20 is received onto the upper end of the barrel 10and a torsion spring 21 is connected between the two elements it) and 20with one end 25 of of spring 21 anchored to element 10 and the other end26 of spring 21 anchored to element 20. A radially projecting pin 22 isthreaded into the barrel 10 and the safety lock barrel 20 defines a slot23 which cooperates with the pin 22. Slot 23 is composed of two fiatportions and an inclined portion which cooperates with pin 22 to obtaina camming effect.

A base 30 is fixed to the upper end of the rod 16 and a series of threejaws 31 are pivotally mounted to the base 30. Each jaw 31 presents a camsurface 32 against which bears a leaf 33 of a three leaf spring elementhaving a hub 38 attached to the top of the rod 16 by means of screw 34.Each leaf 33 defines a double or S-curve with the portion 40 of the leafforming the bottom bend bearing against a cam surface 32. The portion 41of the leaf forming the top bend lies in the space between the jaws 31above the hub 38 of the spring element. Integral with the top of thebarrel 10 are a series of three spaced trigger elements 35 designed andlocated to cooperate with the jaws 31 and in particular the cam surfaces32 of these jaws.

In its at rest position, the rod 16 is withdrawn into barrel 10 underthe influence of spring 19, the base 30 lies in the plane of thetriggers 35 and consequently the jaws 31 are cammed to an open positionagainst the force of leafs 33, and the safety lock barrel is in thecondition shown in Figure l.

The loading of the unit proceeds in the following fashion. The safetylock barrel 20 is turned to shift the pin 22 from the upper flat portionof slot 23 to the lower fiat portion, as seen in Figure 3. This actionloads the torsion spring 21 and the cooperative efforts of the inclinedportion of slot 23 and pin 22 cam the safety lock barrel 2t) axiallyrelative to barrel 10 so that safety lock barrel 20 projects over theend of barrel 10. During movement of safety lock barrel 20, it willengage the under surface of base 30 and cause this part to likewise movein the same direction, away from upstanding members 35. Upon moving ofbase 30, the cam surfaces 32 will disengage from triggers 35 permittingthe leaves 33 to take over control of jaws 31. When the cam surfaces 32fully disengage from triggers 35, the leaves 33 will have pivoted thejaws 31 to a closed position.

Since the base 30 is fixed to rod 16, movement of the former willinvolve a partial withdrawal of rod 16 from the barrel 10 thereby partlyloading spring 19. The force of spring 19 holding base 30 against safetylock barrel 20 coupled with the shape of slot 23 and in particular theposition of pin 22 at the lower fiat portion of slot 23 creates a stablecondition for the unit and it will remain in this condition untildisturbed notwithstanding the fact that torsion spring 21 is loaded.This condiion for the unit is illustrated in Figure 3.

While the unit is in the stable condition as described an antenna wireis anchored by jaws 31; For this purpose an antenna wire adapter 36 toreceive the antenna wire is placed between the jaws 31. Both the adapter36 and the jaws 31 are tapered in order to enhance the gripping action.The antenna wire is now placed in the adapter 36 or secured to it andthe wire is brought to the desired specific loading tension by rotatingsleeve or turnbuckle 11.

With the adapter 36 located between the jaws 31, a further advantage isobtained. The bottom surface of the adapter 36 contacts the portions 41of the leaves 33 displacing them downwardly thereby increasing the forceapplied to cam surfaces 32 by the portions 40 of the leaves 33. Thisfeature ofthe invention is illustrated in Figure 1.

Upon turning sleeve or turnbuckle 11 in the proper direction, the barrel1% will be telescoped down over the sleeve or turnbuckle 11. As thebarrel moves down, the upper edge of safety lock barrel will disengagefrom the base 3% When this occurs, the torsion spring 21 will snap thesafety lock barrel 2t) to its at rest position with pin 22 resting atthe upper flat portion of slot 23. This condition of the safety lockbarrel 2% is illustrated in Figure 1.

During downward movement of barrel 1t] responsive to turning sleeve 11,the compression spring 19 will be compressed between the top of barrel10 and piston 17 with more of the rod 16 showing above the top of barrel10. This occurs by reason of the assembly at the top of rod 16 (base--jaws 31) remaining in a relatively fixed position after the antennawire slack has been taken up. Rod 16 is suitably calibrated by axiallyspaced graduated markings to indicate readings of antenna wire tensionin pounds. When the desired tension is obtained as will be indicated bythe markings on rod 16, a nut 37 threaded onto the sleeve 11 and servingas a lock nut is run up against the lower end of the barrel 10. The unitis now loaded ready for use.

In the event of failure of the antenna wire, the compression spring 19will snap the jaws 31 back against the trigger elements to force thejaws 31 to open and release the antenna wire and adapter 36. Thishappens by virtue of the trigger elements 35 riding on the cam surfaces32, and by this means camming the jaws 31 open against the force ofleaves 33.

Since the unit of the present invention functions to securely anchor anantenna wire and to quickly and efiiciently release the antenna wireupon failure of the wire, damage to and interference with the controlsof the aircraft will be prevented, greatly reducing the accident hazard.

Although the present invention has been shown and described withreference to a specific embodiment, nevertheless various modificationsobvious to one skilled in the art are within the spirit, scope andcontemplation of the invention.

What is claimed is:

1. A wire anchoring and releasing unit comprising a pair of sleevesarranged in threaded telescoping relation, a rod having one end receivedwithin said sleeves and one end partly projecting from said sleeves,resilient means biasing said rod into said sleeves, wire anchoring meansattached to the projecting end of said rod, and trigger means mounted onone of said sleeves in registry with said wire anchoring means adaptedto open said wire anchoring means to release a wire held thereby whensaid wire anchoring means is forced against said trigger means under theinfluence of said resilient means, said unit including a barrel mountedon said pair of sleeves adapted to lift said wire anchoring means out ofengagement with said trigger means.

2. A wire anchoring and releasing unit as defined in claim 1 includingmeans to maintain said sleeves in a relatively fixed position.

3. A wire anchoring and releasing unit as defined in other end, the openends of said barrel and said sleeve being in telescoping threadedengagement, a rod received within said barrel and projecting through theclosed end thereof, pivoted jaw means attached to the projecting end ofsaid rod, .first resilient means biasing said jaw means to a closedposition, a second resilient means bearing till against the closed endof said barrel and the end of said rod within said barrel, said jawmeans defining cam surfaces, and trigger means mounted on said barreladapted to cooperate with said cam surfaces to pivot said jaw means toan open position against said first resilient means in response towithdrawal of said rod into said barrel under the influence of saidsecond resilient means.

6. An antenna wire tension and ejecting unit as defined in claim 5wherein a nut is threaded onto said sleeve adapted to jammed against theopen end of said barrel.

7. An antenna Wire tension and ejecting unit as defined in claim 5wherein said second resilient means is a compression spring.

8. An antenna wire tension and ejecting unit as defined in claim 5wherein said firstresilient means is a spring member including a hubportion and leaf portions.

9. An antenna wire tension and ejecting unit as defined in claim 8wherein each said leaf portion is of a double bend configuration withthe lower bend of said leaf portion bearing against said jaw means andthe upper bend of said leaf portion lies in the space between said jawmeans in a position to be engaged by an element gripped by said jawmeans.

10. An antenna wire tension and ejecting unit as defined in claim 5further including a safety lock barrel received on the closed end ofsaid barrel and defining a slot having a portion inclined to the axis ofsaid barrel, a pin fixed in said barrel and received in said slot and atorsion spring fixed at one end to said barrel and at its other end tosaid safety lock barrel whereby rotation of said safety lock barrel willcause the same to advance axially of said barrel to lift said jaw meansout of engagement with said trigger means against the force of saidsecond resilient means to permit said first resilient means to bringsaid jaw means to a closed position.

11. A wire anchoring and releasing unit comprising a barrel member, anaxially movable rod projecting through an aperture in said barrelmember, wire anchoring means attached to the end of said rod projectingfrom said barrel member, resilient means biasing said rod into thebarrel member, such being the direction tending to bias said wireanchoring means into engagement with said barrel member, and safety lockmeans intermediate said wire anchoring means and said barrel member,said wire anchoring means comprising a plurality of jaw members adaptedto grip the end of a wire to be anchored, means biasing said jaw membersinto gripping relation, and means on said jaw members defining camsurfaces, upstanding members on said barrel member surrounding saidaperture and arranged to engage said cam surfaces of said jaw membersand to move them in the wire-releasing direction when said wireanchoring means has been moved into a position adjacent said barrelmember, said safety lock means being rendered inactive by movement ofsaid wire anchoring means away from said barrel member in response to awire gripped by said anchoring means being placed under tension, wherebyif a tensioned wire gripped by said jaw member breaks, said wireanchoring means will be biased toward said barrel member, with theengagement of said cam surfaces by said upstanding members causing saidjaw members to move so as to release the end of said wire.

12. The wire anchoring and releasing unit according to claim 11including mounting means for said barrel member and tightening meansassociated with said mounting means for causing a wire gripped by saidwire anchoring means to be placed under tension.

References Cited in the file of this patent UNITED STATES PATENTS

